Hmmmm, I really don't think this is true all (or even most of) the time. It probably depends on the task at hand, but if leading small teams of all kinds has taught me anything, it's that I'd prefer a tiny team (or even one person) who is at least above average competence, and is reflective of the work they are doing, than several people of average or below-average competence.

It's eye opening how many people are outright lazy with thought, don't care about the joy of doing something well (apart from whatever extrinsic rewards are attached to the work). Many team members can actually produce negative value.

It seems that people who are really capable of (or care about) conscientious, original thought in problem solving and driving projects forward are few. Count yourself lucky if you get to manage one of these people, they can produce incredible value when well directed.